The present system relates generally to end of train device (EOT) and more specifically to an end of train device for trains having electrically controlled pneumatic (ECP) brake systems.
A combined ECP/EOT end of train device functions to provide RF and/or train line wire communication of pertinent information from the rear to the head end or front of a train. RF mode of transmission of the EOT is that of radio frequencies either in single-directional or two-way communication with a Cab Display Unit (CDU). The RF operation is well known in the rail industry as specified by the Association of American Railroads (AAR) and which some aspects are specified by the Federal Railway Administration (FRA). The standard end of train device is attached to the last car in a train. It includes a battery, a blinking light, a brake pipe pressure sensor, an emergency valve connected to the brake pipe and the RF transceiver.
Train line wire operation, known to the industry as Electrically Controlled Pneumatic (ECP) system, is also known and specified by the AAR. The ECP device on the car is part of a network which includes a transceiver which communicates on the train line and a battery which is charged by the train line. As specified by AAR, the node is activated at a predetermined voltage on the train line and establishes communication with a head end unit (HEU).
While the use of an ECP device at the end of the train to assure safe activation of the high voltage on the train line is shown by U.S. Pat. No. 5,673,876, combined ECP/EOT are shown by U.S. Pat. Nos. 5,873,638 and 6,102,491.
The present end of train device for an electrically controlled pneumatic brake system includes a radio transceiver, a brake pipe sensor, a brake pipe valve, a manual switch and a first controller controlling the radio transceiver and the valve. It also includes a wire transceiver for wire communication over a train line and a second controller connected to and controlling the wire transceiver. The first and second controllers are connected to each other and control the radio transceiver to be active when the wire transceiver is active.
The first controller activates the wire transceiver in response to EPC command signals from at least one of the radio transceiver and the wire. The first controller deactivates the wire transceiver in response to EPC command signals transceiver in response to EPC commands and the second controller maintains the radio transceiver active if a minimum pressure is sensed in the brake pipe.
The first controller activates the wire transceiver in response to EPC command signals from the second controller which is in response to at least one of the radio transceiver receipt of EPC commands and the manual switch. The first controller deactivates the wire transceiver if the EPC command signals from the second controller are in response to the manual switch and an EPC active wire is not detected by the first controller after a preset time period.
The first controller activates and deactivates the wire transceiver in response to EPC commands and the second controller activates the radio transceiver when the wire transceiver is activated if the radio transceiver is not activated and maintains the radio transceiver active if a minimum pressure is sensed in the brake pipe after the wire transceiver is deactivated.
The second controller activates the valve to connect the brake pipe to atmosphere in response to an emergency signal from at least one of the radio transceivers and the first controller which is responsive to the emergency signal from the wire transceiver.
The end of train device includes a pair of batteries connected to a power source terminal for the end of train device; and a power management circuit controlling individually the charging of the batteries from the train line when the end of train device is connected to the train. The power management circuit monitors the voltage and current of each battery. The power management circuit individually isolates the batteries from the power source terminal. The power management circuit includes a power converter connecting the train line and the power source terminal. The power converter may be adapted for train line voltages and public utilities voltages.
These and other aspects of the present device will become apparent from the following detailed description of the invention, when considered in conjunction with accompanying drawings.